An exemplary embodiment relates generally to a method of forming the patterns of a semiconductor device and, more particularly, to a method of forming a pattern that is finer than the exposure resolution limit.
The patterns of a semiconductor device are typically formed using a photolithography process. The photolithography process includes a process of depositing a photoresist layer on an underlying layer for target patterns, a process of exposing the photoresist layer, and a process of developing the exposed photoresist layer. A photoresist pattern is thus formed on the underlying layer through the photolithography process.
The photoresist pattern is used as an etch mask when patterning the patterns of the semiconductor device. Accordingly, the size of the photoresist pattern serves as a factor in determining the size of patterns of the semiconductor device.
The size of the photoresist pattern is determined by the exposure resolution. For this reason, there is a limit to the fineness of the photoresist pattern due to the exposure resolution limit. Consequently, there is a limit to the fineness of patterns of the semiconductor device. For the purpose of highly integrating semiconductor devices, however, there is a need for a scheme for forming a pattern that is finer than the exposure resolution limit.